Here's a vastly expanded version of my (somewhat tongue in cheek) Sunday print column:

I'm talking to you, Arlen Specter. You might want to do yourself a favor by switching teams and joining the Democrats.

Let me start, senator, by lauding your durability. You remind me of the cartoon cockroach in WALL-E, that feisty little survivor of earth's devastation. You've beaten cancer, a brain tumor, and Pat Toomey. (More on him soon.) You've hung tough in a Republican party that doesn't want you anymore, in a state long trending Democratic, and in 2010 you'll celebrate your 30th senatorial year at age of 80.

That means you will have already spent 37.5 percent of your life inside the Cave of Winds, and still you thirst for more. But if you really want to win another six-year term in 2010, keep your title as Pennsylvania's senior senator, and hike that tenure percentage to 42 at the age of 86, you've got to weigh the obvious benefits of renouncing your troubled affiliation with the GOP. Think opportunistically, just as you did way back in '65, when you left the Democrats because you saw the opening to run for Philadelphia D.A. as a Republican.

As you undoubtedly know, there has been buzz in the press for months about you making another switch, but the scenario seems obvious: If you left the GOP now, that target on your backside would disappear, like magic.

Pennsylvania's increasingly conservative Republican electorate is gunning for you - thanks to your support for the Obama-Democratic stimulus plan, your other perceived heresies, and for any heresies yet to come (including your potential support for a hot-button bill making it easier for workers to unionize). They want to take you down in an expensive primary next spring, and perhaps Toomey will be their instrument. In fact, when Michael Steele, the loquacious GOP national chairman, was asked about the idea on Fox News not long ago, he replied, "I'm always open to everything baby, absolutely."

And speaking of recent heresies, here's one that has been largely overlooked by the press: You ticked off the Republican right by voting to confirm Obama nominee David Ogden for the post of deputy attorney general – one of only five Republican senators to do so. The right had targeted Ogden because the guy, in his capacity as an attorney, had once defended Playboy magazine. You voted Yes on confirmation anyway, arguing that lawyers take on all kinds of clients. That didn't cut it with your conservative critics.  As you well recall, you were deluged with anti-Ogden mail.

Undoubtedly, your impulse this year will be to tack rightward in preparation for another tough primary next year. But bear in mind that, no matter how hard you try to reposition yourself, conservative Pennsylvania voters won't buy it anyway. At this point, they're prepared to dismiss anything you do as pander politicking.
You did beat Pat Toomey in a primary back in 2004, by a mere two points, but I doubt that would happen again, if only because so many moderate Pennsylvanians in recent years have left the GOP and signed up with the Democrats. Hundreds of thousands have switched teams. Those were your people; in 2010, they won't be eligible to participate in the primary and help you survive another blood feud.

You spoke recently about that dilemma, saying, "I'm going to deal with it as best I can. I'm trying to get people to change back and be Republicans." Face it, senator, they're not changing back. Not as long as Rush Limbaugh and Sean Hannity are cracking the whip; not as long as their most visible strategic guru is Newt Gingrich, the polarizer who was forced out of power more than 10 years ago.

Senator, most of the remaining Pennsylvania primary voters lean strongly rightward. Last month, 66 percent of statewide Republicans told a pollster that they want you gone. They think of you as "Benedict Arlen." A top conservative group, The Club for Growth (Pat Toomey, president), mindful of your vote on the economic stimulus package, dubbed it "the ultimate act of treason" and has now named you "Comrade of the Month" – thereby demonstrating that Red-baiting has survived the fall of the Soviet Union.

So perhaps you should consider whether it's worthwhile to drain your campaign coffers and put up with this grief. The Republicans seem determined to reduce themselves to a state of powerless purity, so, fine, let them nominate a conservative Senate candidate who would get waxed statewide. And you'd do the waxing, buoyed by the fact that Democrats in Pennsylvania now outnumber Republicans by 1.23 million – more than double the margin of 2004, when you last ran.

Face it, your divorce from the GOP has been in the works for a long time. Remember when you sought the Republican presidential nomination in 1996? Few Americans were even aware of your bid, probably because you never made it to 1996. During the autumn of '95, you assailed the religious right, defended abortion rights, and as a result nobody in the party gave you money. In November you went down to the Florida Republican straw poll, got booed, and flew home. You didn't even stick around for the actual polling of the participants (as I well recall, because I was there).  Because you went AWOL, they tossed you off the ballot. And then, back in Philadelphia, you quit the race.

That whole experience should've told you plenty. And look at the dilemma you'll soon be facing on the hot labor issue I mentioned earlier. When this bill, making it easier for workers to unionize, first came up in the Senate a year ago, you were the sole Republican to back it. Conservatives, notably Gingrich and Toomey, have already put you on notice that a second heresy will not be tolerated when the bill resurfaces this year.

But if you toe the conservative line, in order to make yourself even minimally viable in a Republican primary, you'll burn your longtime allies in organized labor – and there's probably no way you can win in November of 2010, as a Republican in a general election race, without labor money and labor voters. But if you simply switch teams and vote yes on unionization, all these tortured calculations go away.

Maybe you're wondering whether the Democrats would welcome you. Are you kidding?  Ed Rendell and Joe Biden teased you about that idea, right to your face, at a Philadelphia event a few weeks back. They're fully aware, as am I, that no other prospective Democratic senatorial candidate can match your name ID or your war chest; in fact, you're already sitting on $6 million, with the potential to quintuple that amount – a virtual necessity in this expensive media market.

Naturally, not all voters are big fans; some older Pennsylvanians probably remember your lawyerly work defending the lone-assassin scenario for the Warren Commission, when you concocted the ballistic miracle now known as The Magic Bullet Theory and argued that one slug could change direction in midair. And some liberals are probably still ticked about the way you questioned Anita Hill during the Clarence Thomas confirmation hearings in 1991 (although today's 35-year-old Democratic voter probably couldn't care less about that episode, since said voter was only in high school at the time).

Most voters would probably agree that you can use some charisma stimulus. But the bottom line is that if you were pitted against a conservative Republican in November '10, the swing suburban counties around Philadelphia would be yours, and the donor bucks from women and Jewish groups would be yours.
By the way, I wasn't trying to imply earlier that you are a cockroach. It was just a metaphor, and now I'll close with another. Perhaps your savviest political move would be to behave as a chameleon, one of those lizards that can change color when sensing danger. A switch from red to blue might well ensure a longer life.

- With research assistance from UPenn student political writer Emily Schultheis